1. Field of the Invention
The present invention relates generally to a reflective optical unit and a scanner optical system, and more particularly to a reflective optical unit which forms an optical path and is arranged between an object and a lens to secure a conjugate length of a contracted optical system, and a scanner optical system which is suitable for a compact handy scanner used for reading information about an image on a manuscript, etc.
2. Description of Related Art
In a handy scanner which captures image information while moving along a manuscript and illuminating the manuscript with an illumination light source, a light which enters the scanner through a read opening (a slit) is conducted to a line sensor (CCD) via a lens. In order to secure a conjugate length, a plurality of turning mirrors are provided in a casing of the scanner.
In the above-mentioned conventional scanner optical system, the angle of mirrors, which are arranged to secure a necessary conjugate length, must be finely adjusted, and it is extremely difficult to arrange a plurality of mirrors at a proper angle. Moreover, if the number of turns is increased, the number of mirrors also increases, and thus, the scanner optical system cannot be compact.
Furthermore, in order for the scanner to read a clear image, the unevenness of luminance in a light source which illuminates a manuscript must be eliminated, and the manuscript must be efficiently illuminated. In the conventional scanner optical system, a reflective mirror, a lens and a CCD are supported by an independent support mechanism, and thus it is complicated to adjust an optical axis of each member.